1. Field of the Invention
The present invention is in the field of shipping containers. More particularly, the present invention relates to a shipping container and method which are especially adapted to shipping of chip on tape (COT) and tape automated bonding (TAB) integrated circuit chips.
2. Discussion of the Related Technology
Conventionally, integrated circuit chips were provided with electrical connections to their package by use of plural fine-dimension wire bonding conductors. The package included a base portion to which the chip was centrally secured and carried a lead frame with plural conductor leads radiating outwardly from around the chip toward the perimeter of the package base. Near its perimeter the package provided plural depending contact legs or surface mount contact pads to which the lead frame conductors connected and by which electrical contact between the integrated circuit chip and external electrical circuitry was effected. The plural fine-dimension wire bond conductors spanned the distance between the inner ends of the lead frame conductors and the contact pads of the integrated circuit chip itself. Understandably, the placement of these plural fine-dimension wire bond conductors was both labor and time intensive, as well as presenting a primary failure mode for integrated circuits by shorting together of the closely spaced wire bond conductors.
More recently, integrated circuit chips have been provided with electrical connection to their packages by use of a film or tape on which plural conductive traces are formed. The tape has an opening or central area surrounded by a fan or star burst of outwardly radiating conductive traces and into which the small integrated circuit chip is disposed. The integrated circuit chip is physically secured to the tape and electrical connection with the conductive traces is effected by a variety of small scale contact methods. For example, a collapsible solder ball technique may be used to effect electrical connection between the individual contact pads of the integrated circuit chip and the conductive traces of the tape member. Near its outer perimeter, the tape member defines plural individual contact pads which are connected to the inner portions of a package lead frame to effect external electrical connection of the integrated circuit chip much as described above. Understandably, because the tape member provides all of the electrical connections between the package lead frame and the integrated circuit chip, and also carries the integrated circuit chip itself, automated handling of the tape member and chip together during the completion of the packaging process is easier to accomplish.
However, in the manufacture of integrated circuits, it frequently is desirable to fabricate the integrated circuit chips and secure them to their tapes at one facility, so that they may be more easily handled for shipment to another location or facility where the packaging is completed. These integrated circuit chips on their tapes are referred to a "chip on tape" (COT), or "tape automated bonding" (TAB) parts. Because of this desirable sequence of manufacturing steps, industry-standard shipping materials have been developed. These conventional industry-standard shipping materials for COT/TAB parts include a two-part carrier frame, the parts of which nest together like a picture frame to provide a rectangular opening into which the COT/TAB part is received. The COT/TAB part is provided near the perimeter of its tape portion with plural perforations which do not interfere with the conductive electrical traces of this tape portion of the part. The carrier frame is provided with plural projecting pins which are receivable into the perforations of the COT/TAB tape. Consequently, the COT/TAB part spans the rectangular opening of the carrier frame so that the integrated circuit chip is supported during shipping and handling by its own tape portion. The carrier frames are of sufficient thickness (only a fraction of an inch thick) that they may be stacked one atop another without the integrated circuit chips of adjacent carrier frames contacting one another. In fact, the spacing between the adjacent integrated circuit chips is sufficient that they do not contact and damage one another even if the carrier frames are subjected to jostling and physical shock, as may occur in shipping.
In order to make the stacked carrier frames easily handled in shipping, the frames are given a particular external shape with positioning index features, and an elongate industry-standard shipping tube member is configured to accept the stacked carrier frames. This industry-standard shipping tube member is made in a length sufficient to hold a considerable number of carrier frames. For example, the shipping tube members may be made of sufficient length to each carry about 125 carrier frames stacked adjacent one another.
The conventional practice with such carrier frames and shipping tube members when a number of COT/TAB parts less than the full capacity of the shipping tube member is to be shipped is to fill the remaining volume of the shipping tube with empty carrier frames. Of course this practice results in the necessity to buy large numbers of the carrier frames which are not used to actually carry COT/TAB parts. Also, a considerable weight of empty frames is shipped along with each partially full shipping tube member. An alternative has been to simply fill the empty volume of the partially full shipping tube with an inexpensive, light-weight material such as with a plastic foam block. However, this practice results in a risk to the integrated circuit chips because the carrier frames sometimes slip out of place within the shipping tube member so that the integrated circuit chips are damaged.
Also, the use of such foam blocks to fill the empty volume of the shipping tube members is not entirely satisfactory in another respect because the foam blocks have to be cut to size for each shipment in order to accommodate the empty volume of the shipping tube member for that particular shipment. Of course, a variety of different sizes of pre-cut foam blocks could be provided. However, this solution still requires the acquisition and inventorying of a variety of different sizes of foam blocks to account for the differences in shipment sizes using the industry standard shipping tube members and carrier frames.